Breeding report of a new Torreya grandis cultivar ‘Yushanyufei’

Abstract：‘Yushanyufei’is a new cultivar selected from old trees of Torreya grandis in Pan’an county of Zhejiang province. The maternal plant was an old seedling tree, and the progenies were cultivated through asexual reproduction. It was initially selected in 2005 for its more than two eyes’seed nucleus. The maternal plant was discovered in Shanghu town, Pan’an county. Through grafting, planting of ‘Yushanyufei’was expanded whereafter. And the DUS testing finished in 2017. Finally, the new variety of Torreya grandis was registered in 2018 after several years’selection. This cultivar is a tall tree, attaining a height of 15 m. The tree is vigorous with circular or semicircular crown and open tree gesture. Leaves are linear lanceolate, 1.6-3.0 cm long, and 0.3-0.4 cm wide. The upper epidermis of its leaf is dark green and the lower epidermis is light green. It is a dioecism plant. The floral bud is a mixed bud, and ovules are attached to the middle part of bearing branch. The seed is drupaceous and encircled by arillus. The shape of its seed is long obovate oval, and the vascular bundles of aril are straight or twisty . The average single mass of fresh seed is 10.8 g, and the average vertical diameter and horizontal diameter of seed is 3.74 cm and 2.28 cm, respectively. The average index of seed shape is 1.65, and the average peel thickness is 0.35 cm. The average ratio of fresh nut and seed is 36.39%, while the average ratio of dry nut and seed is 67.15%. The mean single mass of fresh nut is 3.9 g. The mean verticaldiameter and horizontal diameter of nut is 3.37 cm and 1.49 cm, respectively. The mean index of nut shape is 2.28, and the mean shell thickness is 0.08 cm. The mean ratio of dry kernel and nut is 66.55%. The mean single mass of dry kernel is 1.6 g, and the fat content of dry kernel is 48.6%. The content of total sugar and protein is 0.83% and 18.02%, respectively. The seed quality is good and the product performance is fine. The anthesis period is mid April, the mature period is mid September of next year, and the seed development period is 17 months in Pan’an, Zhejiang province. Its seedlings and young trees need dank environments and fear high temperature, drought and intense sunlight, but the mature trees are resistant to cold, heat and drought. Its root systems are fleshy, and fear water-logged soil. The SSR molecular markers were used to identify‘Yushanyufei’. The results showed that‘Yushanyufei’and ‘Xifei’had different DNA fingerprint. It is the genetics basis to become a new cultivar. It is suitable for cultivation in Torreya grandis growing areas of Zhejiang province. Its cultivation requirements are the same as Torreya grandis‘Xifei’. It should choose subacidity to neutral sandy soil which is flat and has ability of moisture and fertilizer retention and the altitude should be under 800 m. Virus-free seedlings were planted with row spacing of 4 m×(4-5) m and 450-670 plants per hectare, and the configuration of pollinizer is 5% . For young trees, the tending managements should focus on shading at 5- 9 months, trees management, applying fertilizers. For adult trees, the tending managements should put emphasis on fertilizing, weeding, loosening the soil, increasing the set of fruit, pruning and training properly, strengthening the comprehensive control of pests and diseases.